A reassessment of collections of Marquesan Apocynaceae assigned to the genera Neisosperma Raf., Ochrosia Juss., and Rauvolfia L. revealed that two nomenclatural changes are necessary: 1) transfer of Neisosperma brownii Fosberg & Sachet to the genus Ochrosia, as Ochrosia brownii (Fosberg & Sachet) Lorence & Butaud, comb. nov., and 2) transfer of Ochrosia nukuhivensis Fosberg & Sachet to Rauvolfia as Rauvolfia nukuhivensis (Fosberg & Sachet) Lorence & Butaud, comb. nov. As a result, two species each of Ochrosia and Rauvolfia are recognized from the Marquesas Islands, all endemic. Recent field work has yielded important new data on their distribution, habitat, and conservation status. It is recommended that all four species should be added the IUCN Red List at the Critically Endangered (CR) category.
Keywords: Apocynaceae; French Polynesia; Marquesas Islands; Neisosperma; Ochrosia; Rauvolfia.